Signal transmission surveillance system

ABSTRACT

A system and method of detecting, processing, and selectively responding to radio frequency transmissions detected by at least one projectile deployed above a geographic area.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.12/248,383, filed Oct. 9, 2008, the disclosures of which are expresslyincorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Government Interest. The invention described herein may be manufactured,used and licensed by or for the United States Government.

BACKGROUND OF THE INVENTION

The present invention relates generally to a signal transmissionsurveillance system and, more particularly, to such a system includingan electronic projectile launched over a geographic area for detectingradio frequency transmissions therewithin.

Systems are known for producing radio frequency maps, for example,through the use of a constellation of communication satellites.Illustrative objectives of such systems include providing for moreefficient communications by re-allocating user terminal radio frequencychannels, eliminating the effects of undesirable signals from desirableuser transmission signals, and reducing the power required by the usertransmitter to effectively communicate. Such known satellite basedsystems illustratively use low Earth orbit satellites that communicatethrough one or more terrestrial gateways. As may be appreciated, thesesatellite based systems may have certain geo-spatial and time efficiencylimitations depending upon the number and location of availablesatellites.

SUMMARY OF THE INVENTION

The present invention relates to a field deployable radio frequencysurveillance system. More particularly, the system utilizes anelectronic projectile launched from a hand-held launcher and configuredto detect sources of radio frequency transmissions within a definedgeographic area. Multiple electronic projectiles may be utilized toexpand the desired geographic area of coverage.

According to an illustrative embodiment of the present disclosure, anapparatus for detecting signal transmissions includes an electronicprojectile having a processor, a radio frequency detector operablycoupled to the processor and configured to detect radio frequencytransmission signals, and a transmitter operably coupled to theprocessor and configured to transmit a source signal including dataabout the detected radio frequency transmission signals. An operatorstation includes a receiver configured to receive the source signal, anda controller operably coupled to the receiver and configured to generatea radio frequency transmission map in response to the source signal. Adisplay is operably coupled to the controller of the operator stationand is configured to display the transmission map.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description when takenin conjunction with the accompanying drawings.

FIG. 1 is a perspective view showing an illustrative radio frequencytransmission surveillance system of the present disclosure, with theelectronic projectile launched from a hand held launcher and the descentinhibitor deployed;

FIG. 2 is a perspective view similar to FIG. 1, showing a signaltransmission detected by the electronic projectile, signals transmittedbetween the electronic projectile and the base station, and the locationof the signal transmission determined by the base station;

FIG. 3 is a cross-sectional view in partial schematic of the electronicprojectile of FIG. 1;

FIG. 4 is a transverse cross-sectional view of the electronic projectileof FIG. 3;

FIG. 5 is a block diagram showing the interaction of variousillustrative elements with the processor of the electronic projectile ofFIG. 1;

FIG. 6 is a perspective view in partial schematic of the base station ofthe surveillance system of FIG. 1;

FIG. 7 is a block diagram showing interaction of various illustrativeelements with the controller of the base station of FIG. 6;

FIG. 8 is a top plan view of an illustrative embodiment radio frequencytransmission map generated by the surveillance system of FIG. 1;

FIG. 9 is an illustrative view of a radio frequency transmission mapdisplayed through the lenses of a pair of binoculars;

FIG. 10 is a diagrammatic representation of a geographic area undersurveillance by a plurality of surveillance systems;

FIG. 11 is a diagrammatic view showing integration of the surveillancesystem of FIG. 1 with command nodes and a global information grid; and

FIG. 12 is a flow chart of an illustrative method of operation of thesurveillance system of FIG. 1.

Corresponding reference characters indicate corresponding partsthroughout the several views. Although the drawings representembodiments of various features and components according to the presentdisclosure, the drawings are not necessarily to scale and certainfeatures may be exaggerated in order to better illustrate and explainthe present disclosure. The exemplification set out herein illustratesembodiments of the invention, and such exemplifications are not to beconstrued as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE DRAWINGS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings, which are described below. The embodiments disclosed beloware not intended to be exhaustive or limit the invention to the preciseform disclosed in the following detailed description. Rather, theembodiments are chosen and described so that others skilled in the artmay utilize their teachings. It will be understood that no limitation ofthe scope of the invention is thereby intended. The invention includesany alterations and further modifications in the illustrated devices anddescribed methods and further applications of the principles of theinvention which would normally occur to one skilled in the art to whichthe invention relates.

Referring initially to FIGS. 1 and 2, an illustrative embodiment radiofrequency transmission surveillance system 10 is shown as including adeployable, illustratively an electronic projectile 12. The electronicprojectile 12 is configured to be launched in the air from aconventional hand-held projectile launcher 14 operated by a user 15. Asfurther detailed herein, a variety of different users 15, such as asoldier, a rescue worker, or a telecommunications technician, mayoperate the surveillance system 10 depending upon its particularapplication.

The electronic projectile 12 illustratively has a caliber definedbetween 20 mm and 100 mm, and typically about 40 mm. As such, theelectronic projectile 12 may be used in conventional projectile launcher14, such as the M203 grenade launcher or the MGL-140 multi-shot grenadelauncher. More particularly, the projectile launcher 14 includes alaunch tube 16 configured to receive and discharge the electronicprojectile 12. While a handheld launcher 14 is shown in FIG. 1, othersuitable launchers may also be used. For example, the launcher 14 may beground supported. Alternatively, the user 15 may cause a balloon 52(further detailed below) to deploy and inflate as the projectile 12 ispositioned on, or at a certain predetermined elevation above (e.g., fivefeet), the ground. As further detailed herein, the electronic projectile12 is in communication with a base or operator station 18, through aphysical connection when in a docked mode of operation and through awireless connection when in a deployed mode of operation.

With reference to FIGS. 3 and 4, the electronic projectile 12illustratively includes a housing 20 including a cylindrical side wall22 coupled to a base 23 and supporting a nose 24. A conventionalpropellant 26 is received within the housing 20 and is configured todrive the projectile 12 in motion. More particularly, the propellant 26is configured to launch the electronic projectile 12 from the launchtube 16 of the projectile launcher 14 into a given trajectory 28 above amonitored area 30 (FIG. 1). When in this deployed mode of operation, theelectronic projectile 12 is configured to detect RF signal sources 31within the monitored area 30 (FIG. 2).

With reference to FIGS. 3 and 5, controller or processor 32 is receivedwithin the housing 20 and is operably coupled to a power source 34, suchas a battery. The processor 32 illustratively includes an internal clock33 (FIG. 5). A volatile or temporary memory (RAM) 35 a is incommunication with the processor 32 for storing mission sensitiveinformation. As a security precaution, should the power source 34 fail,information stored within the volatile memory 35 a will be lost and, assuch, may not be retrieved. The volatile memory 35 a illustrativelyincludes projectile configuration details, such as desired surveillancemodes (e.g., RF, video, audio, etc.), frequency surveillance details(e.g., bands for detection), and security protocols (e.g., encryptiondata and digital certificate data), which may be uploaded from theoperator station 18, as further detailed herein. A non-volatile orpermanent memory 35 b may also be in communication with the processor 32for storing non-sensitive information. The non-volatile memory 35 b maybe preprogrammed with basic operating and communications software.

A shock absorber 36 is illustratively received within the housing 20 forprotecting internal components, particularly electronics such as theprocessor 32, from potentially damaging forces during launch andoperation of the projectile 12. The shock absorber 36 may comprise anyconventional resilient device for absorbing forces, such as a steel coilspring, a gas shock absorber, or an elastomeric disc.

A location detector 40 is operably coupled to the processor 32 and isconfigured to detect the location of the projectile 12 and provide alocation signal 42 indicative thereof to the processor 32. In oneillustrative embodiment, the location detector 40 comprises a globalpositioning system (GPS) receiver including an associated antenna 46. Itshould be noted that in the illustrative embodiment, the GPS receivermay be part of the processor 32 or a separate component coupled thereto.As is known, the GPS receiver, through its antenna 46, receives signalssent by a constellation of GPS satellites (not shown) orbiting theearth. Each satellite continually transmits signals including the timethe signal was sent and the orbit for the satellite transmitting thesignal. The processor 32 uses the arrival time of each signal tocalculate the distance to each satellite, from which it determines theposition of the electronic projectile 12. More particularly, theprocessor 32 may determine x, y, and z coordinates (corresponding tolatitude, longitude and altitude) of the electronic projectile 12 fromthe signals received by the location detector 40.

The electronic projectile 12 further includes a descent inhibitor 50operably coupled to the processor 32. The descent inhibitor 50 is storedwithin the nose 24 of the housing 20 during a stored mode of operationand is deployed outside of the housing 20 during a surveillance mode ofoperation. The processor 32 illustratively controls deployment of thedescent inhibitor 50. In one illustrative embodiment, the descentinhibitor 50 comprises a balloon 52 in selective fluid communicationwith a gas supply 54, illustratively a container containing lighter thanair gas, such as helium or hydrogen. The processor 32 is operablycoupled to a control valve 56 positioned intermediate the gas supply 54and the balloon 52. More particularly, the processor 32 is configured toopen the control valve 56 for filling the balloon 52 from the gas supply54. In a further illustrative embodiment, the descent inhibitor 50comprises a parachute (not shown) deployed by an explosive charge. Inboth illustrative embodiments, the descent inhibitor 50 opposes theforce of gravity, thereby causing the electronic projectile 12 to hoveror float above the monitored area 30 for an extended period of time(FIG. 1).

In one illustrative embodiment, the processor 32 causes the descentinhibitor 50 to deploy when the projectile 12 has reached the maximumelevation or apex 58 of its trajectory 28. Such maximum elevation 58 maybe determined by the processor 32 in response to signals received by thelocation detector 40. As detailed above, altitude is one of thecoordinates (z coordinate) detected by the GPS receiver 44.Alternatively, a separate altimeter (not shown) may be operably coupledto the processor 32 for detecting the maximum height of the electronicprojectile 12.

In certain illustrative embodiments, the electronic projectile may alsoinclude a trajectory control system (TCS). In one illustrativeembodiment, the TCS is defined by the control valve 56 controlled by theprocessor 32. More particularly, the control valve 56 may be a threeposition valve with a first position providing fluid communicationbetween the gas supply 54 and the balloon 52 (i.e., supply position), asecond position providing fluid communication between the balloon 52 andatmosphere (i.e., venting position), and a third position preventingfluid flow to and from the balloon 52 (i.e., closed position). Forexample, the control valve 56 may be placed in the venting position inresponse to a command signal received from the operator station 18 toallow the projectile to descend to the ground for retrieval.Additionally, the control valve 56 may be placed in the supply positionby the processor 32 in order to release more gas into the balloon overtime as gas particles escape through the pores of the balloon materialover time in order to maintain a desired altitude over the observationarea.

In another illustrative embodiment, the TCS may comprise a tetherdefined by spool of high tensile strength material (wire or plasticline) attached to the projectile housing 20 as it is launched from thelauncher 14. As the projectile 12 moves away from the launcher 14, thewire will unravel from the spool thereby allowing the projectile 12 toreach a desired elevation without restriction. After the descentinhibitor 50 deploys, the user may secure the tether to the ground withan anchor or stake. The tether prevents the projectile 12 from floatingout of the desired geographic area.

In yet another illustrative embodiment, the TCS may comprise alift-generating device, such as a wing, suspended on a tether from theballoon 52. More particularly, the wing generates a horizontal liftforce that can be directed over a wide range of angles. This force, astransmitted to the balloon 52 by the tether, alters the balloon's path.An example of such a TCS is the StratoSail® System detailed by GlobalAerospace Corporation of Altadena, Calif.

A surveillance device, illustratively a radio frequency (RF) detector 60including an antenna 72 a is operably coupled to the processor 32 and isconfigured to detect signals 62 transmitted by RF signal transmissionsources 31 (FIG. 6), including frequency and signal identification data.In different illustrative embodiments, the RF detector 60 may be part ofthe processor 32 or a separate component coupled thereto. The RFdetector 60 provides detection signals 64 indicative of the detectedsignals 62 from radio frequency signal transmission sources 31 to theprocessor 32. The detector 60 may include a tunable band filter (notshown) controlled by the processor 32 for detecting a variety ofdifferent RF bands. In a further illustrative embodiment, a bandconverter (not shown) may be used to convert the detected signal bandfrequency for subsequent signal processing and/or transmission.

Illustratively, the processor 32 cooperates with the internal clock 33to timestamp the detected radio signal 62. In other words, the processor32 records the time the signal 62 was detected. The processor 32 mayalso cooperate with the internal clock 33 to record the duration oftransmission of the signal 62.

In one illustrative embodiment, the processor 32 is configured to detectthe identification of the source 31 transmitting an RF signal 62. Forexample, in the case of a cellular phone, the processor 32 is configuredto detect the ESID (Electronic Security Identification), sometimesreferred to as an ESN (electronic serial number), which is embeddedwithin the phone by the manufacturer. As is known, each time a call isplaced, the phone's identification is transmitted to a base station sothat the wireless carrier can check the call's validity. In certaininstances, the processor 32 will transmit a signal to query cellularphones 31 within the monitored area 30 thereby causing the cellularphones 31 to transmit their respective identifications (ESIDs or ESNs).

A transmitter, illustratively a transceiver 66 including an antenna 72 bis operably coupled to the processor 32. The processor 32 is configuredto cause the transceiver 66 to send an RF source signal 68 to theoperator station 18 (FIG. 6). The source signal 68 includes informationor data from the location signal 42 and the detection signal 64. Moreparticularly, the source signal 68 includes information or data on thelocation of the electronic projectile 12 and on the detected RFtransmission signal sources 31. In other words, the transceiver 66 sendsRF source signal 68 to the operator station 18 with the informationrecently collected by the projectile 12 (including, for example, signaltimestamp, signal duration, signal frequency, and signal thumbprint, andlocation of projectile housing 20 (e.g., GPS coordinates)).

The source signal 68 is illustratively encrypted through software withinvolatile memory 35 a as described above. More particularly, the sourcesignal 68 may be encrypted in accordance with Advanced EncryptionStandard FIPS 140-2 in order to provide for integrity andconfidentiality. Filtering, illustratively OSI Layer 2, may also be usedto allow only authorized nodes (i.e., receivers and/or transmitters) tocommunicate with the electronic projectile 12. Digital certificates maybe stored within volatile memory 35 a and embedded within the sourcesignals 68 to ensure signal authenticity upon receipt by the operatorstation 18.

With further reference to FIGS. 3 and 4, a plurality of antennas 72extend axially within the housing 20 of the electronic projectile 12.Illustratively, four antennas 72 a, 72 b, 72 c, and 72 d are shown,although the number and orientation of the antennas may vary based uponthe particular applications of the electronic projectile 12. As notedabove, antenna 72 a may be operably coupled to the RF detector 60 toreceive RF signals within a desired band. For example, the antenna 72 aand associated detector 60 may be configured to detect cellular phonesignals, typically transmitted within the 1800 MHz and 1900 MHzfrequency bands. Further illustratively, antenna 72 b may be operablycoupled to the transceiver 66 to send and receive signals from theoperator station 18. The remaining antennas 72 c and 72 d may beutilized for other application specific requirements. For example,antenna 72 c may be used to receive RF transmission signals within thecitizens band (CB), illustratively between 26.96 MHz and 27.41 MHz,while antenna 72 d may be used to receive other RF transmission signals,such as those used by two-way radios (or walkie-talkies) or othercommercial bands. In one illustrative embodiment, antenna 72 d may beused for receiving and/or transmitting RF commercial transmissions on2.4 GHz and/or 5.8 GHz bands. Antenna 72 d, or additional antennae, mayalso be used to receive and/or transmit additional cellular phonetransmissions on 800 MHz and/or 900 MHz bands. Alternatively, antennamay be used to jam or interfere with frequencies or send corrupted datato interrupt or jam signals from a specific frequency, as furtherdetailed herein. A summary of illustrative uses of the antennas 72 areprovided in the following table:

ANTENNA COUPLING FUNCTION 72a RF Receiver Receive cellular phone signals(1800 MHz and 1900 MHz bands) 72b RF Transmitter Transmit signals tobase station 72c RF Receiver Receive CB radio signals (26.96 MHz-27.41MHz) 72d Application Receive/Transmit RF Signals on Specific variousbands (e.g. RF commercial (illustrative 2.4 GHz and 5.8 GHz bands, RFReceiver cellular phone 800 MHz and or Transmitter) 900 MHz bands)

As shown in FIGS. 3 and 5, the housing 20 of the electronic projectile12 may include a number of surveillance devices 74 in addition to the RFdetector 60. Such surveillance devices 74 may include a camera 74 aand/or an audio receiver or microphone 74 b. Illustratively, the camera74 a may be a video camera, a night vision camera, and/or an infrared(IR) camera. The surveillance devices 74 are in communication with theprocessor 32 such that information may be processed and transmitted bythe transceiver 66. More particularly, video and/or audio feeds may bestreamed to the operator station 18 within the source signal 68. Thevideo and/or audio feeds may also be stored within the volatile memory35 a or permanent memory 35 b of the electronic projectile 12 forsubsequent download and evaluation by advance teams prior to othersentering the monitored area 30. As noted herein, only authorized nodeswill be able to receive the source signal 68 through the use of securityelements, such as encryption, filtering, and digital certificates.

With further reference to FIGS. 3 and 5, the electronic projectile 12may further include one or more responders 76 controlled by theprocessor 32. In one illustrative embodiment, the responder comprises adestructive or anti-tamper device 76 a, illustratively an incendiarydevice or an explosive, that may be detonated by the processor 32 inresponse to a predefined stimuli or trigger event. For example, if thelocation detector 40 senses an uncontrolled descent of the electronicprojectile 12, the processor 32 may detonate the destructive device 76 ato prevent unauthorized access to the components of the electronicprojectile 12.

In a further illustrative embodiment, the responder 76 comprises an RFjamming device 76 b configured to disrupt RF communications at a certainfrequency within the monitored area 30. More particularly, the RFjamming device 76 b may comprise an RF transmitter coupled to theprocessor 32 and tuned to the same frequency as the RF signal source 31of interest and with the same type of modulation to interfere with,suppress, or disrupt any signal 62 at the RF signal source 31. In oneillustrative embodiment, antennae 72 d may be used to jam frequencies orsend corrupt data. Illustratively, scrambled signals or irregularitiesin the modulation may be used to interfere with or jam signals from aspecific frequency (for example jamming a 2.4 GHz signal coming from atransmitter by sending corrupted data on the same frequency to confusethe associated receiver). Illustratively, the RF jamming device 76 b maybe directed to certain cellular phones with ESIDs or ESNs previouslyidentified by the processor 32. In other embodiments, identification ofcertain suspect ESIDs or ESNs themselves may be the trigger eventcausing activation of the responder 76 by the processor 32.

Referring now to FIGS. 6 and 7, the operator station 18 illustrativelyincludes an RF detector 75 including an antenna 77 configured to detectsignals 62 transmitted by RF signal transmission sources 31. The RFdetector 75 may function in a manner similar to the RF detector 60 ofthe projectile 12. More particularly, the RF detector 75 providesdetection signals 79 indicative of the detected signals 62 transmittedby the RF signal transmission sources 31, including frequency and signalidentification data. The illustrative operator station 18 furtherincludes a projectile transceiver 80 having an antenna 82 for providingcommunication with the electronic projectile 12. As such, thetransceiver 80 is configured to receive the source signal 68 from theelectronic projectile 12. Similarly, the transceiver 80 is configured totransmit a control signal 81 to the electronic projectile 12. It shouldbe appreciated that the frequency used for transmitting signals 68 and81 between the projectile 12 and the operator station 18 should bedifferent from the frequencies monitored by RF detectors 60 and 75 orjammed by the jamming device 76 b.

A controller 84 is operably coupled to the RF detector 75 and to thetransceiver 80. More particularly, the controller 84 processesinformation or data received from within the detection signal 79 fromthe RF detector 75 and the source signal 68 as transmitted by theelectronic projectile 12. The controller 84 illustratively includes amaster clock 85. The controller 84 cooperates with the master clock 85to timestamp and record duration of signals 62 detected by the RFdetector 75.

A user input 86, such as a keyboard 88, and a user output 90, such as adisplay screen 92 are in communication with the controller 84. Alocation detector 94, illustratively a GPS receiver including an antenna98, are coupled to the controller 84. As further detailed herein, sincethe controller 84 includes absolute location information of theelectronic projectile 12 (from the location detector 40) and theoperator station 18 (from the location detector 94), it can determinethe distance separating the projectile 12 and the operator station 18.The controller 84 then compares the thumbprints for detected signal(s)62, from data within detection signal 79 and source signal 68, todetermine that the signal(s) 62 are from the same RF signal source 31.Once the signal(s) 62 have been identified, the location data of theprojectile 12 and the operator station 18, together with the signal timestamps are used to calculate through triangulation the absolute locationor coordinates of the RF transmission source 31 (FIG. 2).

The controller 84 may include a memory 100 storing operating software102, such as data collection software configured to cause the controller84 to aggregate data from and assign data points to various RFtransmission sources 31. The information aggregated by the controller ofthe operator station 18 may be output in a variety of manners. In oneillustrative embodiment, mapping software 104 may also be stored in thememory 100 and used to position the identified RF signal transmissionsources on a graphic representation or map 106 (FIG. 8).

With reference to FIG. 8, the map 106 may be viewed by the user 15 on auser output 90, such as display screen 92 coupled to the controller 84.More particularly, the illustrative map 106 provides an aerial view ofthe monitored area 30 with the detected RF signal sources 31 identifiedby an indicia or symbol. Details of each signal source 31, such astransmission frequency, duration, and/or ESID or ESN, may be called upto the screen 92 by clicking on the symbol representing the signalsource 31.

In a further illustrative embodiment, the user output 90 may includebinoculars 110 (FIG. 9) including a display screen 112 having anelectronic overlay 114 that may display location data of signal sources31 received from the controller 84 via a wireless network signaltransmitted by an output receiver, illustratively the transceiver 80.Illustratively, the binoculars 110 may comprise electronic distanceranging binoculars including an electronic compass and a distanceranging device (not shown). As noted above the binoculars 110illustratively receives data processed by the operator station 18 via awireless network signal. More particularly, the binoculars 110 include aprocessor in communication with the display screen 112 and a locationdetector, illustratively a GPS receiver (not shown). The processor ofthe binoculars 110 determines the location of the binoculars 110 andgenerates the image shown on the screen 112 through a variety of datasources. Such data sources may include the GPS receiver, the compass,the ranging device, and the operator station 18 to provide the overlay114 on the screen 112.

As detailed herein, the projectile 12 and the operator station 18 areillustratively configured to detect RF signals 62. The controller 84 ofthe operator station 18 may be further configured to generate controlsignal 81 in response to a trigger or stimulus. More particularly, thecontroller 84 is looking for predefined trigger events. These predefinedtrigger events may be stored in memory 100 in a mission specific threatlibrary. If a trigger match is found, the controller 84 causes thetransceiver 80 to transmit the control signal 81 to the transceiver 66of the electronic projectile 12. The processor 32 of the electronicprojectile 12 may respond in a number of ways in response to the controlsignal 81 sent in response to the trigger event. For example, theprocessor 32 may take no action, or may activate responder 76 uponreceiving proper instructions from the control signal 81. As detailedabove, the responder 76 may include a number of active elements,including a destructive device and/or an RF jamming device.Alternatively, the processor 32 could cause activation of one or more ofthe surveillance devices 74 (such as camera 74 a and/or audio receiveror microphone 74 b) and/or an alarm.

The operator station 18 further includes a docking station 120 operablycoupled to the controller 84. The docking station 120 illustrativelyincludes a base 122 supporting a cylindrical housing or receiver 124 forreceiving the electronic projectile 12. The receiver 124 includeselectrical connectors 126, illustratively annular contact rings, forcontacting mating electrical contacts or connectors 128 supported by theside wall 22 of the projectile 12. In one illustrative embodiment, fourseparate connectors are provided for mating with the projectile 12, in asimilar fashion as a universal serial bus (USB). Illustratively, two ofthe connectors may be used for data communication with the processor 32,and the remaining two connectors may be used for charging the battery34. A printed circuit board 130 is supported by the base 122 and couplesthe connectors 126 with the controller 84.

The operator station 18 is configured to negotiate with the projectile12. Cryptographic keys are used to make sure the operator station 18 isvalid and that the projectile 12 is valid. In other words, the operatorstation 18 and the projectile 12 may communicate only if theirrespective cryptographic keys are valid. Encryption may be used toencrypt data at rest when the projectile 12 is not being used.

The operator station 18 may communicate with the projectile 12 tofacilitate a variety of services. For example, the operator station 18may download audio and video stored in the projectile 12. The operatorstation 18 may also probe the projectile's memory 35 to determine iftrigger events or stimuli have been discovered while the projectile 12was operating in a “scarecrow” mode. The scarecrow mode is defined whenthe operator station 18 directs the projectile 12 to move over ageographic area and record audio, video, and/or RF signals. If theprojectile 12 loses communication with the operator station 18, itsfunction will not be affected. When the scarecrow mode is enabled, theprojectile's processor 32 is instructed to deploy the destructive device76 a if a detected altitude is too low or if the location detector 40detects that the projectile 12 is outside of its operational range.

With reference to FIG. 10, multiple electronic projectiles 12 may bedeployed to expand the effective monitored area 30 and create a coveragenet 78. The coverage net 78 may be used to not only expand the monitoredarea 30, but may also be used to facilitate communication betweenmultiple electronic projectiles 12 thereby providing relaycommunications in geographically challenging environments (e.g.,mountains, tall buildings, etc.).

A plurality of different electronic projectiles 12 are shown in FIG. 10to provide coverage net 78 over expanded monitored area 30 ofapproximately X miles by Y miles. The monitored area 30 may be expandedor contracted by deploying more or fewer electronic projectiles 12,respectively. Each operator station 18 has a unique identificationnumber assigned to it. Similarly, each electronic projectile 12 has aunique identification number assigned to it and stored within its memory35 b. For example, the nineteenth projectile 12 launched from theoperator station 18 identified as unit fifty is identified as projectilenumber 5000019, while the eighty-sixth projectile 12 launched from thesame operator station 18 is identified as projectile number 5000086.Similarly, the two-hundred thirty-ninth projectile 12 launched fromoperator station number seventy-seven is identified as 77000239.

With reference to FIG. 11, the controller 84 may also includecommunication software 108 to facilitate communication between theoperator station 18 and one or more electronic projectiles 12 and/or oneor more central command stations 134. More particularly, the controller84 of each operator station 18 may send and receive data to and from oneof the command stations 134 a, 134 b, 134 c, 134 d. The command stations134 a, 134 b, 134 c, 134 d may each be in active communication with anetwork 136, such as the global information grid (GIG) or worldwide web,through output transceiver, illustratively a two-way tactile radio 116.More particularly, the tactical radio 116 may be used for communicatingwith a C2 (Command and Control) platform, a C4I (Command, Control,Communications, Computers, and Intelligence) platform, or some othersecure network 136 to upload and download information for intelligencegathering and/or sharing.

With reference to FIG. 12, during operation of the surveillance system10, a user 15 initially docks the electronic projectile 12 with thedocking station 120 of the operator station 18, as shown in block 202.More particularly, the housing of the electronic projectile 12 isreceived within the receiver of the docking station 120 such that theelectrical connectors 126 and 128 provide communication between theprocessor 32 of the projectile 12 and the controller 84 of the operatorstation 18. At block 204, the projectile 12 is synchronized with theoperator station 18. For example, software and mission specific data(e.g. audio/video download, projectile memory download, cryptographickey exchange, firmware update, threat library, control data, etc.) isuploaded from the operator station 18 to the memory 35 a, 35 b of theprojectile 12. Data may also be downloaded from the memory 35 a, 35 b ofthe projectile 12 to the operator station 18, for example, at the end ofa mission. Such downloaded data may be used to create new or updateexisting threat libraries.

During this synchronization step, time is synchronized between the clock33 of the projectile 12 and the master clock 85 of the operator station18. More particularly, the processor 32 of the projectile 12 and thecontroller 84 of the operator station 18 determine the difference intime between the clocks 33 and 85 and assign this time difference valuea variable in the memory 100 of the operator station 18, based upon theassigned projectile 12 (for example, projectile serial number in casethe operator station 18 is monitoring multiple projectiles 12).Synchronizing or accounting for time differentials between the clocks 33and 85 of the projectile 12 and the operator station 18, permits therespective processor 32 and controller 84 to determine how long aspecific signal 62 takes to reach each location. This information isneeded to calculate and triangulate distances to the transmission sourcebased on signal communication times, and thereby determine thetransmission source 31 location.

Next, the projectile 12 is undocked from the operator station 18 andloaded into the projectile launcher 14 at block 206. The user 15 atblock 208 then launches the electronic projectile 12 from the launcher14. The electronic projectile 12 travels along trajectory 28 away fromthe launcher 14. At block 210, the location detector 40 monitors GPScoordinates. Upon reaching maximum elevation 58 as detected by thelocation detector 40 and determined by processor 32 at block 212, theprocessor 32 deploys the descent inhibitor 50 at block 214. Moreparticularly, the processor 32 opens the control valve 56 therebyfilling the balloon 52 with gas from the gas supply 54. At this point,the electronic projectile 12 hovers above the geographic area 30 to bemonitored.

The radio frequency detector 60 of the electronic projectile 12 scansthe area for RF signal sources 31 at block 216. Upon detecting RFsignals, the processor 32 uses the clock 33 to timestamp the signal 62and record signal duration. The processor 32 also may record the signal62 thumbprint (unique identification). Finally, the processor 32attaches the location determined by the location detector 40(illustratively GPS coordinates) of the projectile 12 at the time thesignal 62 was received. As detailed above, additional monitoring may beconducted by other surveillance devices, such as a video camera and/oran audio receiver, which provides video and/or audio data to theprocessor 32. The source signal 68, including data on absolute locationof projectile 12, timestamp of transmitted RF signals, frequency of RFsignal sources 31, and duration of transmitted RF signals, is thentransmitted at block 218 by the transceiver 66 to the controller 84 ofthe operator station 18. In instances where cell phone signal sources 31are identified, cell phone identification numbers (ESID or ESN) may alsobe included in the source signal 68. Additional surveillance data, suchas video and/or audio data may also be transmitted in source signal 68.

The transceiver 80 of the operator station 18 receives the source signal68 from projectile 12. The controller 84 utilizes the security devices,such as encryption digital certificates, and/or filtering, to verify theauthenticity of the source signal 68. The operator station 18 receivesthe same signal 62 from the signal source 31 and records the same dataas the projectile 12, including receipt time of the signal 62 and signalduration. The absolute locations of both the projectile 12 and theoperator station 18 are then used to determine the distance separatingthe projectile 12 and the operator station 18. The controller 84 of theoperator station 18 compares the thumbprint from the signal(s) 62detected at both the projectile 12 and the operator station 18, anddetermines whether the signal(s) 62 is the same. Once the signal(s) hasbeen determined to be the same, the location coordinates and time delaysfrom the projectile 12 and the operator station 18 are computed by thecontroller 84 to give a triangulation position of, and intercept vectorto, the signal source 31. In other words, the controller 84 triangulatesthe signal source 31 and then assigns it a data point and a geospatiallocation at block 220.

Once data points are collected for all of the known signal sources 31,the controller 84 of the operator station 18 may relay the data back toa command unit or to the global information grid for command decisionand/or information gathering. Data may also be relayed to various useroutputs, such as the electronic binoculars 110 or display screen 92, formapping relative to the location of the operator station 18. Thebinoculars 110 may be used to find the target visually, where it can beflagged as threat or benign from visual prompts on overlay 114 of thebinoculars 110. The user 15 may visually identify targets on the overlay114, whereby the user 15, or others having access to the data throughoperator station 18, command station, or global information grid, mayscroll through targets and identify as friend or foe.

As shown at block 222, upon detecting an appropriate stimulus or triggerevent, the controller 84 will match the detected trigger event to acorresponding predefined trigger event stored in the threat library. Atthis point the controller 84 will caused the transceiver 80 to transmita signal back to the processor 32 of the electronic projectile 12 toactivate at least one responder 76. The stimulus or trigger event mayillustratively comprise any one of a frequency location, a frequencymovement, and a frequency duration. The stimulus or trigger event mayalso comprise a particular cellular phone of interest as identifiedthrough its ESID or ESN. In one illustrative embodiment, the responder76 comprises a jamming signal which is transmitted at block 224 by theelectronic projectile 12. In a further illustrative embodiment, theresponder 76 comprises an explosive which is detonated in response tothe signal from the operator station 18.

As may be appreciated, the illustrative radio frequency transmissionsurveillance system 10 as detailed herein may be used in a wide varietyof environments for numerous different purposes. In militaryapplications, the system 10 may provide RF mapping of hostile areas inorder to locate enemy combatants and/or improvised explosive devices(IEDs) with RF triggers. The system 10 may also provide video and audiosurveillance or reconnaissance for military, law enforcement, and/orsearch and rescue users. As detailed above, the system 10 may alsoprovide for smart RF jamming in order to prevent undesirable RFcommunications. In communications applications, the plurality ofprojectiles 12 may be useful in providing communication relays indifficult environments, such as mountainous regions. The system 10 maybe integrated into a global information grid thereby providing themapping of RF signals, including cellular phone ESIDs. In allapplications, live encrypted data feeds may be provided from theprojectile 12 to various operator stations 18 on the ground.

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

1.-31. (canceled)
 32. A method of performing radio frequency surveillance, the method comprising the steps of: launching an electronic projectile over a defined area; detecting radio frequency signals within the defined area; monitoring for trigger events; and activating a responder in response to detected trigger events.
 33. The method of claim 32, further comprising the step of inhibiting descent of the electronic projectile.
 34. The method of claim 32, further comprising the step of transmitting a source signal to a operator station.
 35. The method of claim 34, further comprising the step of generating a radio frequency transmission map in response to the source signal.
 36. The method of claim 32, wherein the trigger events comprises at least one of a frequency location, a frequency movement, and a frequency duration.
 37. The method of claim 32, wherein the trigger event comprises an action in response to a stimuli.
 38. The method of claim 32, wherein the step of activating a responder comprises transmitting a jamming radio frequency signal.
 39. The method of claim 32, wherein the step of activating a responder comprises detonating an explosive.
 40. A method of performing radio frequency surveillance, the method comprising the steps of: launching an electronic projectile over a defined area; the electronic projectile detecting a radio frequency signal within the defined area, and timestamping the detected radio frequency signal; determining the location of the electronic projectile at the time the electronic projectile detects the radio frequency signal; providing an operator station in communication with the electronic projectile; the operator station detecting the radio frequency signal, and timestamping the radio frequency signal; determining the location of the operator station at the time the operator station detects the radio frequency signal; and calculating the location of the source of the radio frequency signal based upon the timestamps of the radio frequency signal, the location of the electronic projectile at the time the electronic projectile detected the radio frequency signal, and the location of the operator station at the time the operator station detected the radio frequency signal. 